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Unread 11-03-2007, 10:35 AM   #1
gsxr150
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Tire width and PSI discussion.

I see the Laredo's includes 235/65R17 tires, and Limited has 245/65R17.

If I were to get new tires in the future, would there be a problem going with 245's? (stock wheels)

Also, what PSI do you guys recommend? Or should I just go off the door?

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Unread 11-03-2007, 11:05 AM   #2
gsxr150
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Update, according to most tire websites you can use the 245's no problem on a Laredo. I wonder why they do that...? Visual Marketing?
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Unread 11-03-2007, 01:52 PM   #3
goose1
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245s were the optional size for the laredo for 05-06. 245s are now standard on all WKs.
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Unread 11-03-2007, 09:05 PM   #4
HurriJeff
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I run 265/65 17's gsxr150.

The correct pressure for any tire is quite a variable. If your using OEM tires you want to pretty much follow the door's recommendation but if you use a different brand of tire you'll need to do some extensive research and testing to find the "correct" pressure. Also, there is no correct pressure for all different loads, driving conditions and tires. What your looking for is a pressure that works for your Jeep under the conditions that it is driven in. These guidelines should help you get close and keep you from getting too far outside operating range.

(1) Never exceed the listed max pressure listed on the tire.

(2) Greater loads require more pressure up to the max pressure but not over so if your carrying heavy stuff air up your tires to max.

(3) A reduction of 10%-15% is normally safe for tires to soften the ride when your not carrying a load.

(4) Higher pressure (not to exceed max) will usually reduce rolling resistance and improve fuel economy but may result in a less comfortable ride.

(5) Heat is the enemy of a tire. A tire with low pressure will get very hot from the flexing and the added friction on the road caused by distortion of the side walls and tread where is squashes down at the bottom where it contacts the road. You'll have to talk to the mfg of any particular tire to find out whats too hot. Low tire pressure is the cause of 90% of blowouts in tires that are within service limits and not otherwise damaged. If your tires are bald or showing cords you probably already know what causes the other blowouts.. get new tires.

(6) Check your pressure monthly and check them when the tire is (cold) at ambient outside air temperature. Pressure can rise 4 or more psi at speed from cold. Pressure readings taken on a hot tire can be expected to be higher than normal and can and will exceed the rated max. The manufacturer knows pressure can exceed the listed max when they are hot and takes pressure rise into account when they rate the tire.

Personally I run 34 psi cold in my tires and they rise to 37-38 psi at 75mph.
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Unread 11-03-2007, 09:14 PM   #5
gsxr150
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Quote:
Originally Posted by HurriJeff
I run 265/65 17's gsxr150.

The correct pressure for any tire is quite a variable. If your using OEM tires you want to pretty much follow the door's recommendation but if you use a different brand of tire you'll need to do some extensive research and testing to find the "correct" pressure. Also, there is no correct pressure for all different loads, driving conditions and tires. What your looking for is a pressure that works for your Jeep under the conditions that it is driven in. These guidelines should help you get close and keep you from getting too far outside operating range.

(1) Never exceed the listed max pressure listed on the tire.

(2) Greater loads require more pressure up to the max pressure but not over so if your carrying heavy stuff air up your tires to max.

(3) A reduction of 10%-15% is normally safe for tires to soften the ride when your not carrying a load.

(4) Higher pressure (not to exceed max) will usually reduce rolling resistance and improve fuel economy but may result in a less comfortable ride.

(5) Heat is the enemy of a tire. A tire with low pressure will get very hot from the flexing and the added friction on the road caused by distortion of the side walls and tread where is squashes down at the bottom where it contacts the road. You'll have to talk to the mfg of any particular tire to find out whats too hot. Low tire pressure is the cause of 90% of blowouts in tires that are within service limits and not otherwise damaged. If your tires are bald or showing cords you probably already know what causes the other blowouts.. get new tires.

(6) Check your pressure monthly and check them when the tire is (cold) at ambient outside air temperature. Pressure can rise 4 or more psi at speed from cold. Pressure readings taken on a hot tire can be expected to be higher than normal and can and will exceed the rated max. The manufacturer knows pressure can exceed the listed max when they are hot and takes pressure rise into account when they rate the tire.

Personally I run 34 psi cold in my tires and they rise to 37-38 psi at 75mph.

Wow, thanks for the great information! I'm guessing you have a bigger engine than the 3.7. I would not mind getting 265, but the extra weight is something I probably don't need, haha.
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Unread 11-03-2007, 09:26 PM   #6
HurriJeff
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Why would you guess that my engine is bigger.. wont your 3.7 do 75mph !!! Rofl !
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Unread 11-03-2007, 10:03 PM   #7
gsxr150
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Ahh, I see that now...you have the HEMI. Any additional weight on the wheels makes a huge difference. I know this because I have a wrangler with 33's. I'm just assuming that a 265 will weight a bit more than 245.

Don't be picking on my 3.7. ; )
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Unread 11-04-2007, 07:51 PM   #8
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Jeff hit it right on, I run 40 in mine, its not over the max and I like the firmer ride. Just because we have Hemi's doesn't mean we can go any faster. My top speed is 112 MPH governer limited. Your 3.7 will go just as fast, just won't be as quick.
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Unread 11-04-2007, 09:01 PM   #9
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I suppose she might be a little more peppy with 40 then say 32...I'll try a few test runs.
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Unread 11-07-2007, 11:05 AM   #10
Jojeep
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Are your 265's fitting on the stock set up? I guess my question whould be what is the largest size tire I can fit on my stock 06 GC?

Thanks.
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Unread 11-08-2007, 08:04 PM   #11
HurriJeff
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My WK is lock stock ! No lift, no spacers and no modifications what so ever.
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Unread 11-08-2007, 09:30 PM   #12
nfs060
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Do you think we can run 225/65-17 for a pure winter tire. I live in a snow climate so the thinner the tire the better the snow traction.
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Unread 11-08-2007, 09:36 PM   #13
KingPrat
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Just realize that the tire is slightly smaller than the 235 or 245 (speed difference). 65 is a percentage of the width


A skinnier tire will fare better in the snow than a wider tire. It'll cut through the snow and get a little better grip.
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Unread 11-08-2007, 09:47 PM   #14
nfs060
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Yes it will be slightly smaller. Do you think it will make a difference, handling or 4x4, besides the speedometer being slightly off?
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Unread 11-09-2007, 10:38 AM   #15
MarkoPo
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I don't think 10MM of width will make much of a difference. If you're into math take your total weight divide it by four and divide that number by how much tread is touching the ground in square inches. Then figure the same with a 10mm narrower tire. I have no idea, but I'm guessing won't be much of a difference. Maybe 3 or 4 pounds per square inch? I'd go with the wider tires and let the four wheel drive do it's job. If you get a tire with a more aggressive tread it has less surface contact then a street tire. This makes a difference as well. But you are correct that a tall skinny tire does the best in snow.
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